Control of Viral Contamination of Food and Environment

Cliver, Dean O.

In some of the poorer parts of the world, the nutrients in human urine and feces are essential to food production. More affluent nations may prefer alternatives, but ''night soil'' fertilization represents the ultimate in sustainable agriculture. There are certainly some health risks from recycling waste; however, in sufficiently isolated communities, herd immunity may afford protection against many bacteria and viruses, though not against parasites. As communities grow and involvement in food production decreases, there is likely to be an informal phase of waste disposal, such as emptying slop jars out of second-story windows as was done in cities long ago (cf. gardyloo in many English-language dictionaries). This clearly entails a threat to public health; bacterial diseases spread in this way, such as typhoid and cholera, apparently obscured the risk of virus transmission. There are now options for dealing with human waste, close to the point of origin (onsite treatment), for isolated households and very small communities (Crites and Tchobanoglous 1998) . These may have significant capital costs, but provide the best available alternative with limited means at hand.